I have the older (heavier) steel body truck with Max Payload that has heavier axels and springs. With this I tow an 8000 loaded trailer 30’ long. I am within all specs and it works well.
Let’s look at your numbers quick like.
GVWR 7000 - 6280 = 720 payload available.
Trailer loaded will come in at 8500+.
Tongue weight will be at around 1100+.
With this trailer you would be over payload and rear axle ratings. I would shop around for a smaller trailer.
And good job asking before you bought the trailer.
Good luck,
Stu
2012 F150 HD/Max Payload (8200 GVWR, 2176 payload) SuperCrew EcoBoost
2008 Komfort Trailblazer T254S